Mesoaortic compression of the left renal vein (the so-called nutcracker syndrome): Repair by a new stenting procedure

Anatomical variants of the retroaortic left renal vein

BACKGROUND

Anatomical variants of the left renal vein (LRV), such as the retroaortic (RLRV) and circumaortic (CLRV) course, are of surgical importance. Different morphological and topographical possibilities of the RLRV could occur. It was aimed at documenting the anatomical variables of the RLRV.

METHOD

A retrospective study on 375 computed tomography angiograms was performed. Five different anatomical types of LRV were documented: preaortic types 1 and 2 and retroaortic types 3-5.

RESULTS

In 344/375 cases, preaortic LRVs were found. In 31/375 cases, different types of RLRV were found: type 3a - single RLRV, 41.94%; type 3b - single RLRV with bifid caval end, 9.68%; type 3c - single RLRV with trifid caval end, 3.23%; type 4a - CLRV with extrahilar origin, 29.03%; type 4b - CLRV with renal sinus origin, 12.9%; type 5 - triple LRV (one preaortic LRV and two RLRVs), 3.23%. Reference vertebral levels were recorded for the prevertebral segment of the RLVR. The vertebral level of type 3a varied from the L1/L2 disc to the upper third of the L4 vertebra. Type 3b was found in 3/31 RLRV cases; in one of these, the hemiazygos vein was inserted by two roots into the LRV and its upper caval end trunk. There was a significant statistical association between type 3b and the vertebral level, all cases being centered on the middle third of the L4 vertebra.

CONCLUSIONS

New morphological possibilities of the LRV were distinguished, and a new anatomical classification system of the RLRV results. The RLRV variant should be documented case-by-case as it has its anatomical variables.

Systematic review of endovascular versus laparoscopic extravascular stenting for treatment of nutcracker syndrome

OBJECTIVE

The aim of the present study was to assess the current strategies of endovascular and laparoscopic extravascular stenting for symptomatic compression of the left renal vein (LRV), most frequently between the aorta and superior mesenteric artery (nutcracker syndrome [NCS]).

METHODS

We performed a systematic review of all studies of endovascular and laparoscopic extravascular LRV stenting for NCS using the PubMed/MEDLINE, Scopus, Embase, Cochrane, Science Citation Index Expanded, Emerging Sources Citation Index, and Epistemonikos databases. Data were collected in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analysis) guidelines. The English, Spanish, and German language literature was searched from January 1, 1946 to February 9, 2022. The outcomes assessed included symptom resolution, hematuria resolution, and reintervention at follow-up.

RESULTS

The search yielded 3498 reports. After removing the duplicates and those without the full text available, 1724 studies were screened. Of these, 11 studies were included in the present review. Of the 11 studies, 7 were on endovascular stenting and 4 on laparoscopic extravascular stenting; all 11 studies were retrospective, single-center case series. Of the 233 patients, 170 (80 women) had undergone endovascular stenting and 63 (9 women) had undergone extravascular stenting. The follow-up period varied from 1 to 60 months after endovascular stenting and 3 to 55 months after extravascular stenting. The symptoms had resolved in 76% (range, 50%-100%) after endovascular stenting and 83% (range, 71%-100%) after extravascular stenting. Hematuria had resolved in 86% (range, 60%-100%) after endovascular stenting and 89% (range, 77%-100%) after extravascular stenting. Of 185 patients, 9 had required reintervention after endovascular stenting and none after extravascular stenting.

CONCLUSIONS

Endovascular and laparoscopic extravascular stenting are less invasive and, thus, more attractive treatment options that have been more recently developed for the management of NCS. The results from the present study have shown that symptom and hematuria resolution must be provided before they can be considered preferred management options for patients affected by NCS. Given the limited number of patients involved, no definitive conclusion could be drawn regarding the superiority of one technique compared with the other.

Laparoscopic placement of left renal vein extravascular stenting in treatment of nutcracker syndrome: Techniques and long-term outcomes

OBJECTIVES

We aimed to assess the feasibility and efficacy of laparoscopic extravascular stent in treatment of nutcracker syndrome by transperitoneal or retroperitoneal approach.

METHODS

Seventy-six patients with nutcracker syndrome were retrospectively enrolled from a tertiary referral center, and underwent transperitoneal (63 patients) or retroperitoneal (13 patients) laparoscopic extravascular stent from March 2011 to December 2020. Surgical parameters, complications, imaging and clinical outcomes were collected and analyzed.

RESULTS

All procedures were successfully carried out without open conversion. The median operation time, estimated blood loss, and postoperative hospital day were 120 (interquartile range [IQR]: 90-144) min, 20 (IQR: 10-30) ml, and 7 (IQR: 6-9) days. At a median follow-up of 52 (range: 9-127) months, 60 (79%) patients had complete symptom resolution, 14 (18%) patients had significant symptom improvement, and 2 (3%) patients reported no symptom improvement. Ninety-four percent (50/53) of hematuria, 91% (30/33) of proteinuria, and 89% (25/28) of flank/abdominal pain resolved after extravascular LRV stenting. No significant differences were detected in surgery parameters and recovery rates of clinical symptoms between two approaches (each p > 0.05). However, patients with transperitoneal approach need longer to achieve complete recovery compared with retroperitoneal approach (8.7 vs. 1.5 months, p = 0.016).

CONCLUSIONS

Laparoscopic extravascular stent performed either transperitoneally or retroperitoneally is a feasible and effective option in treatment of nutcracker syndrome. Retroperitoneal laparoscopic extravascular stent required shorter time to achieve complete recovery, which should be considered whenever possible in surgical decision-making.

Interventional Management of a Rare Combination of Nutcracker and Wilkie Syndromes

Nutcracker and Wilkie syndromes are rare mesoaortic compression entities, and their association is even less common. Data on interventional treatment of these pathologies are still scarce, but results from limited case series are encouraging. We report the case of a previously healthy 45-year-old woman diagnosed with nutcracker and Wilkie syndromes who presented with macroscopic hematuria, intermittent pain in the left flank and hypogastric region, postprandial nausea, and unexplained significant weight loss. A successful endovascular approach with stent implantation in the left renal vein was performed, but the stent migrated toward the left kidney, and this acute complication was managed through an interventional strategy as well. At the three-month follow-up, the patient described a marked improvement in all symptoms, except for the macroscopic hematuria. As it was our strong belief that the approach was efficient, we further investigated the “hematuria”, which eventually led to the diagnosis of endometrial carcinoma. A hysterectomy and bilateral adnexectomy were planned, and chemoradiotherapy was initiated with the goal of preoperative tumor reduction. To our knowledge, this is the first reported case in which both Wilkie and nutcracker syndromes were effectively treated by stent implantation in the left renal vein, complicated with very early stent migration due to inadequate apposition to the less compliant venous lumen. The treatment of the duodenal compression was indirectly included in the stenting of the left renal vein, as reclaiming the venous lumen widened the aortomesenteric angle. The aim of this review is to discuss our center’s transcatheter experience with these rare disorders and explore the literature in order to establish the benefits and limitations of such an approach.

Bibliometric and visual analysis of research on nutcracker syndrome from 1974 to 2021: A systematic review

BACKGROUND

At present, researchers have obtained fruitful results in the study of nutcracker syndrome (NCS), but there is still a lack of systematic research on the overall status of this disease. This article aims to describe the past and current status of research into NCS, and predict future research trends and popular research topics.

METHODS

Using bibliometric and visualization methods, 552 articles related to NCS collected from the Scopus database from 1974 to 2021 were analyzed from multiple perspectives.

RESULTS

Overall, the amount of literature related to NCS is on the rise every year, and the number of citations is the turning point in 2006. The United States has the largest number of publications and has the most extensive cooperation with other countries. The main contents of the co-authored study focused on the symptoms, surgical procedures, and concomitant diseases of NCS. Keywords such as peak velocity, ultrasonography, orthostatic proteinuria, etc appeared earlier, whereas diagnosis, chronic pelvic pain, endovascular stents, etc appeared later.

CONCLUSIONS

The literature utilization rate of NCS is relatively insufficient. The pathogenesis and pathological mechanisms need to be further studied, and the diagnostic criteria and surgical methods will continue to be favored by clinicians.

Surgical treatment of abdominal compression syndromes: The significance of hypermobility-related disorders

Case reports and systematic studies of the most common hypermobility-related disorders, hypermobile Ehlers-Danlos syndrome (hEDS), and hypermobility spectrum disorder (HSD) typically describe gastroenterological symptoms and complaints attributed to structural malfunction, autonomic dysfunction, or inflammation of the gastrointestinal tract. However, abdominal compression syndromes (CS) may also contribute to pain and dysfunction in these individuals and be the leading pathology given symptoms significantly reduce or cease after decompressive surgery. Arising not only in the abdomen and causing pain (median arcuate ligament syndrome [MALS] and superior mesenteric artery syndrome [SMAS]), CS also occur in the retroperitoneum and the pelvis (nutcracker syndrome and May-Thurner syndrome), these latter conditions causing chronic pelvic congestion syndrome (PCS). Here, we report primarily on our experience of the assessment and management of MALS and SMAS in a cohort of cases with a surprising prevalence of HSD and hEDS. To our knowledge, this is the first cohort report of its kind in hEDS, HSD, and CS. We recommend that CS are considered in hEDS and HSD individuals with gastrointestinal and other painful complaints within the "belt" area. These CS can be identified using functional ultrasound duplex examination in experienced hands, and in appropriate cases stabilizing surgery can substantially improve quality of life.

Sonographic Evaluation of Pelvic Venous Disorders

ABSTRACT

Pelvic venous disorders are a group of interrelated conditions characterized by venous incompetence. These conditions often manifest with nonspecific symptoms that overlap with many gynecological, gastrointestinal, and urologic diseases. Clinical diagnosis can be difficult, and imaging can play a vital role in differentiating etiology. Sonographic evaluation is often the first step in evaluating these symptoms. Special attention to possible underlying pelvic venous disorders can reveal characteristic findings, support diagnosis, and guide treatment. Here we review pelvic congestion syndrome, nutcracker syndrome, May-Thurner syndrome, and other venous disorders, with a specific focus on sonographic findings and considerations.

Pelvic congestion syndrome and May-Thurner syndrome as causes for chronic pelvic pain syndrome: neuropelveological diagnosis and corresponding therapeutic options

Objective

To report on diagnosis and management of pelvic congestion including the May-Thurner syndrome (MTS) as potential etiologies for intractable pelvic neuropathic pain.

Design

Retrospective study of women presented with intractable pelvic neuropathic pain, who had left sided venous uterine plexus above 6mm with reversed and slow flow on Doppler, with dilated arcuate veins passing through the uterine muscle. Those with suspicion of MTS underwent further radiological investigations and if applicable, endovascular interventions.

Intervention

61 consecutive patients were included. 14 with visceral pain presumed to be caused by Pelvic Congestion Syndrome were treated by ovarian vein embolization. An improvement of pain was observed in all patients – mean pain reduction of 3.93 points, from 7.21 (±1.42; 4-10) to 3.28 pts (±1.54; 1-6) over 6 months (p<0.01). 47 presented with pelvic somatic neuropathic pain; 19 underwent endovascular intervention (angioplasty, stenting) and finally all of them a laparoscopic exploration/decompression of the sacral plexus and the endopelvic portion of the pudendal nerves, with an overall VAS reduction from 8.56 (±1.1712;7-10) to 2.63 (±1.53; 0-6) at one-year- follow-up (p<0.01).

Conclusion

Laparoscopic exploration/decompression of the nerves seems to be effective in a carefully selected group of patients. Endovascular interventions for pelvic somatic neuropathies may not be an effective treatment. We recommend that Doppler studies of the uterine vessels are performed as an extension to gynaecological examination in women with intractable pelvic pain.

Nutcracker Syndrome: How to Diagnose It and When/How Should It Be Treated in the Pelvic Venous Disease Population

With wider recognition of left renal vein compression / obstruction, especially as an incidental finding, the significance as it relates to the patient's symptoms needs to be evaluated in light of variable practices and results of treatment. This communication deals with problems of diagnosis, clinical significance, options and indications for treatment.

From Nutcracker Phenomenon to Nutcracker Syndrome: A Pictorial Review

Left renal vein (LRV) entrapment, also known as nutcracker phenomenon if it is asymptomatic, is characterized by abnormality of outflow from the LRV into the inferior vena cava (IVC) due to extrinsic LRV compression, often accompanied by demonstrable lateral (hilar) dilatation and medial (mesoaortic) stenosis. Nutcracker syndrome, on the other hand, includes a well-defined set of symptoms, and the severity of these clinical manifestations is related to the severity of anatomic and hemodynamic findings. With the aim of providing practical guidance for nephrologists and radiologists, we performed a review of the literature through the PubMed database, and we commented on the definition, the main clinical features, and imaging pattern of this syndrome; we also researched the main therapeutic approaches validated in the literature. Finally, from the electronic database of our institute, we have selected some characteristic cases and we have commented on the imaging pattern of this disease.

'Full prosthetic jacket': external stenting of the renal vein

Introduction: We present a case of positional compression of the left renal vein (LRV) after right nephrectomy and caval reconstruction, treated by external stenting using a reinforced vascular prosthesis.Case report: A 69-year-old female patient presented because of swelling of the left leg. A renal cell carcinoma (RCC) was visualized on computed tomography (CT) scan in the right kidney, with a thrombus occluding the inferior caval vein (ICV) and the right renal vein (RRV). A right nephrectomy was performed, with ligation of the already occluded ICV. Venotomy allowed thrombectomy of the ICV above the level of the renal veins. Venous return from the left kidney was secured by reconstruction of the confluence of the LRV and the ICV. Postoperatively, urinary output declined, leading to anuria and elevated levels of serum creatinine. With surgical exposition of the LRV, a flow of 387 mL/min was measured. After removal of exposition, flow in the LRV dropped to 51 mL/min. The positional compression was treated with a reinforced vascular PolyTetraFluoroEthylene (PTFE) prosthesis placed around the LRV.Discussion: Besides some reports on external stenting of the renal vein in the treatment of nutcracker syndrome (NS), this is the first report describing this technique outside this clinical entity.

Gonadal vein transposition is a safe and effective treatment of nutcracker syndrome

BACKGROUND

Nutcracker syndrome (NCS) is a pelvic venous disorder that results from outflow obstruction of the left renal vein, most often due to a decreased aortomesenteric angle, leading to gonadal vein reflux, pain, and varices. Although a number of open and minimally invasive procedures to treat NCS have been described, the optimal management of this condition remains uncertain. To the best of our knowledge, we have presented the largest case series to date using gonadal vein transposition (GVT) to treat NCS.

METHODS

Patients considered for intervention to treat NCS underwent a rigorous and standardized workup, including axial imaging studies, catheter-based diagnostic procedures, and urinalysis. GVT has been the institutional first-line treatment of NCS for appropriate patients. With institutional review board approval, a retrospective review of patients who had undergone GVT for NCS was conducted.

RESULTS

From 2014 to 2019, 18 GVTs had been performed. Of the 18 patients, none had died or required reintervention, although 2 had required readmission. During a median follow-up of 178 days, complete symptom relief was achieved in 11 patients (61.1%), with 4 patients (22.2%) reporting partial symptom relief and 2 (11.1%) reporting transient symptom relief.

CONCLUSIONS

GVT is a safe and effective procedure to treat NCS in appropriately selected patients with outcomes that compare favorably with those of other described procedures. Appropriate patient selection for this procedure is critical and requires a rigorous and standardized approach to diagnosis and management.

Doppler US and CT Diagnosis of Nutcracker Syndrome

Nutcracker syndrome (NCS) is a syndrome caused by compression of the left renal vein (LRV), between the abdominal aorta and the superior mesenteric artery, resulting in hypertension of the LRV and hematuria. Doppler ultrasonography (US) has been commonly used for the diagnosis of NCS. However, several technical issues, such as Doppler angle and sample volume, need to be considered to obtain satisfactory results. In addition, morphologic changes of the LRV and a jetting phenomenon across the aortomesenteric portion of the LRV on contrast-enhanced computed tomography (CECT) are diagnostic clues of NCS. With proper Doppler US and CECT, NCS can be diagnosed noninvasively.

Renal autotransplantation results in pain resolution after left renal vein transposition

Left renal vein transposition is often the preferred treatment of nutcracker syndrome. However, pain returns in some patients despite surgery. One solution to this problem is renal autotransplantation. Here we report our initial results of renal autotransplantation in patients with persistent flank pain despite a previous left renal vein transposition. We used the University of Wisconsin loin pain hematuria syndrome test as a diagnostic maneuver to determine who may benefit from renal autotransplantation; this procedure subsequently resulted in complete pain resolution in all three patients. All patients underwent successful renal autotransplantation and remain pain free. These cases support the test as a diagnostic maneuver to determine which patients may benefit from renal autotransplantation.

Nutcracker syndrome: A proposed ultrasound protocol

BACKGROUND

Nutcracker phenomenon (NCP) describes the compression of the left renal vein between the aorta and the superior mesenteric artery. Nutcracker Syndrome (NCS) refers to the clinical manifestations of NCP.

AIMS

This paper aims to provide education and ultrasound protocol for Clinicians and Sonographers who encounter patients with the symptoms of NCS during their course of practice.

METHODS

The following report examines two case studies where a diagnosis of NCP was made from clinical history and ultrasound findings. Based on these case studies, we would like to propose an appropriate ultrasound scanning protocol for patients presenting with symptoms of gonadal vein incompetence.

RESULTS

The above case studies highlight the need for further assessment with ultrasound to help diagnose cases of NCP.

CONCLUSION

The proposed ultrasound techniques are a valid protocol extension to the ultrasound examination to help diagnose NCP.

Robot-assisted laparoscopic extravascular stent for nutcracker syndrome

Minimally invasive treatment options are a safe and feasible alternative for treatment of nutcracker syndrome. Endovascular stenting has shown promising long-term resolution of symptoms but can be complicated by stent migration or thrombosis. Laparoscopic extravascular stent placement has shown promising results with the potential to avoid these complications. We report the first case of extravascular stent placement using the robotic approach for the treatment of nutcracker syndrome.

Venous Compression Syndromes: a Review

OPINION STATEMENT

Venous compression syndromes present a diagnostic and therapeutic challenge as the clinical presentation can be vague, diagnostic criteria are often not present, and high quality standardization of when and how to treat is not available in part due to the limited number of cases reported and also due to the limited literature available. Significant venous compression should be considered when clinical symptoms correlate to location of compression and there is evidence of hemodynamic changes including venous hypertension, collateral/variceal formation, and/or thrombus formation. In general, treatment of venous compression should address the etiology of the compression as opposed to just treating symptoms associated with it such as significant varices or anticoagulation for thrombus to avoid recurrence of symptoms.

Nutcracker Syndrome: Case Report on the Management of Recurrent Stenosis After Stenting

Nutcracker syndrome is a clinical entity leading to renal venous hypertension due to extrinsic compression of the left renal vein by the superior mesenteric artery. Current surgical therapy involves placement of an oversized renal vein stent with partial protrusion into the inferior vena cava (IVC) to relieve stenosis and prevent stent migration. Here, we present a patient with intractable pain and hematuria secondary to nutcracker syndrome who underwent left renal vein stent placement and developed recurrent symptoms due to flow-limiting kinking at the left renal hilum, with partial obstruction of the IVC from pseudointimal hyperplasia. This was treated with stent excision and construction of a left neorenal vein bypass. Thus, given these complications, we should perhaps revisit the recommendations for oversizing of the stent.

Micro- and macroscopic hematuria caused by renal vein entrapment: systematic review of the literature

BACKGROUND

Hematuria secondary to renal vein entrapment is mentioned only passing in textbooks and reviews.

METHODS

We performed a search of the National Library of Medicine database for peer-reviewed publications using the terms "renal vein" or "nutcracker" and "hematuria".

RESULTS

We identified 187 published reports/studies that covered 736 patients, of whom 288 had microscopic hematuria and 448 had macroscopic hematuria. The patient cohort comprised 159 patients aged ≤17 years. Abdominal pain was absent in  approximately 65% of all patients, and a clinically relevant left-sided varicocele was observed in 29% of the male patients. A normal pre-aortic left renal vein and an anomalous anatomy were noted in 680 and 56 patients, respectively. The body mass index (BMI) was lower in patients with renal vein entrapment than in the controls, with a regression of hematuria correlating with an increase in BMI. A surgical procedure was attempted in 34% of the patients, of which the most common were endovascular stenting and transposition of the renal vein distally into the vena cava.

CONCLUSIONS

In cases of unexplained hematuria with or without abdominal pain, clinicians should consider the diagnosis of renal vein congestion, especially in males with varicocele. Ultrasonic Doppler flow scanning is the recommended initial diagnostic modality in these patients. Expectation management is advised in the great majority of cases.

Extravascular stent management for migration of left renal vein endovascular stent in nutcracker syndrome

Background

Nutcracker syndrome is an entity resulting from left renal vein compression by the aorta and the superior mesenteric artery, which leads to symptoms of hematuria or left flank pain. The alternative option of endovascular or extravascular stenting is very appealing because of the minimal invasive procedures. Stents in the renal vein can cause fibromuscular hyperplasia, proximal migration or embolization.

Case presentation

A 30-year-old female was diagnosed with nutcracker syndrome for severe left flank pain. After failed conservative approach, she underwent endovascular stenting and subsequently developed recurrent symptom for stent migration one month postoperatively. She underwent successful extravascular stenting with complete symptom resolution.

Conclusion

The extravascular stenting is an alternative option after migration of left renal vein endovascular stenting. The computed tomographic imaging was closely correlated to therapeutic interventions and stent migration.

Postsurgical Follow-up for a Repaired Nutcracker Syndrome

Nutcracker syndrome is a venous entrapment phenomenon characterized by the impingement of the left renal vein between the superior mesenteric artery and abdominal aorta. Treatment, if necessary, consists of surgical intervention. In the case presented, a young female presented at an outpatient vascular surgical center for surveillance of a surgically repaired nutcracker syndrome. A renal sonogram was performed to evaluate patency and hemodynamics of the left renal vein. Color and spectral Doppler were used to evaluate the left renal vein as well as the left kidney to document appropriate renal perfusion.

[Nutcracker syndrome - treated by surgery]

The nutcracker syndrome is caused by tight compression of the left renal vein between the superior mesenteric artery and the abdominal aorta. The consequences may vary between symptomfree conditions through moderate proteinuria and hypertension to severe hematuria. All imaging modalities have been used during diagnostic workup. Wide varieties of surgical and endovascular solutions are reported aiming to achieve decompression of the renal vein like venous or arterial transposition, bypass, renal autotransplantation, stenting, nephrectomy, etc. In our case a 21-year-old man the nutcracker syndrome was successfully solved by transposition of the superior mesenteric artery into the infrarenal aorta.

Prevalence and incidence of clinical symptoms of the retroaortic left renal vein

OBJECTIVE

To analyze the prevalence and incidence of clinical symptoms of retroaortic left renal vein (RLRV) diagnosed incidentally over 10 years by computed tomography (CT).

PATIENTS AND METHODS

7,929 consecutive patients (out- and inpatients) were studied with multidetector CT from January 2000 to April 2011. We retrospectively reviewed RLRV patients' medical records and analyzed their clinical characteristics.

RESULTS

A total of 61 out of 7,929 patients had a RLRV, therefore the prevalence was 0.77%. Only 4 of 61 (6.6%) RLRV patients diagnosed by CT scan were clinically symptomatic. RLRV was associated with flank pain and microhematuria in one patient (1.6%), in another one with microhematuria only and in one with ureteropelvic junction obstruction. Furthermore, one patient suffered from arterial hypertension associated with a RLRV.

CONCLUSIONS

RLRV is a rare finding, and only a small minority of RLRVs causes symptoms.

Retroperitoneal laparoscopic reimplantation of the left renal vein for nutcracker syndrome

OBJECTIVE

To describe the feasibility of retroperitoneal laparoscopic reimplantation of the left renal vein (LRV) for nutcracker syndrome (NCS).

PATIENTS AND METHODS

Two patients with NCS underwent the surgery. Both patients complained of gross hematuria and flank discomfort that could not be relieved by resting. They were placed in a supine position and 5 ports were placed in the right abdominal wall. The procedures were performed with a retroperitoneal approach. The LRV was transected and then reimplanted into the distal inferior vena cava.

RESULTS

The procedures were performed successfully without any major complications. The total operation time was 105 and 120 min, respectively. Hematuria and flank discomfort were resolved after the surgery. Ultrasonography revealed a patent lumen without compression.

CONCLUSIONS

Retroperitoneal laparoscopic reimplantation of the LRV appears to be a feasible procedure with satisfactory short-term outcomes.

Transposition of the left renal vein for the treatment of nutcracker syndrome in children: a short-term experience

BACKGROUND

Nutcracker syndrome is caused by compression of the left renal vein between the superior mesenteric artery and the aorta. Invasive surgical intervention for this pathologic entity is controversial, particularly in the pediatric population. We aim to describe our early clinical and operative experience with such patients.

METHODS

We report 3 cases of pediatric patients undergoing successful left renal vein transposition for the treatment of nutcracker syndrome.

RESULTS

All 3 patients were female (age 9-17 years) and presented with a mean of 11.7 months of abdominal or left flank pain requiring chronic narcotic analgesia. Initial clinical presentations were associated with either hematuria or proteinuria. Diagnosis of nutcracker syndrome was supported in each case by an elevated renocaval pressure gradient and/or axial imaging demonstrating mesoaortic compression of the left renal vein. All patients underwent open surgical repair, which included left renal vein transposition, liberation of the ligament of Treitz and associated adhesions, as well as excision of periaortic nodal tissue (mean hospital length of stay 5.7 days). After mean follow-up of 13 months, all patients report complete resolution of symptoms and hematuria/proteinuria.

CONCLUSIONS

Transposition of the left renal vein is a safe and effective treatment for nutcracker syndrome in appropriately selected pediatric patients. Further experience and long-term follow-up are warranted to better evaluate the sustained efficacy of this procedure in this unique patient population.

Retroperitoneal laparoscopic extravascular stent placement for renal nutcracker syndrome: initial experience

OBJECTIVE

To report our initial experience in treating renal nutcracker syndrome by retroperitoneal laparoscopic extravascular stenting.

PATIENTS AND METHODS

Two male patients, aged 13 and 16 years, were diagnosed with nutcracker syndrome and received retroperitoneal laparoscopic extravascular stent placement. The perioperative data were collected and evaluated. The follow-up was 10 and 18 months.

RESULTS

Both procedures were successful without obvious complications. Total operative time was 65 and 50 min, estimated blood loss was 110 and 70 ml, and postoperative hospital stay was 4 and 6 days. The symptom of gross hematuria ceased 3 and 6 days after surgery. Both patients had normal findings during follow-up.

CONCLUSIONS

Treatment of nutcracker syndrome by retroperitoneal laparoscopic extravascular stent placement is a safe and feasible procedure, especially for youngsters in the period of physical development. Longer follow-up and further experience are needed to evaluate the efficacy of this procedure.

Infrarenal abdominal aorta aneurysm: a rare cause of anterior nutcracker syndrome with associated pelvic congestion

We present a rare case of anterior nutcracker syndrome caused by an abdominal aorta aneurysm (AAA). A 61-year-old woman was admitted to our institution for computed tomography angiography. It revealed an AAA 51 mm in diameter that was lifting off of the left renal vein toward the superior mesenteric artery, causing anterior nutcracker syndrome with consequent left renal vein compression and left ovarian vein congestion. Aneurysm resection was performed, followed by left ovarian vein ligation and left adnexectomy to prevent vein conglomerate rupture. This is the first case that describes anterior nutcracker syndrome caused by AAA, which was successfully treated by aneurysm resection.

Venous compression syndromes: clinical features, imaging findings and management

Extrinsic venous compression is caused by compression of the veins in tight anatomic spaces by adjacent structures, and is seen in a number of locations. Venous compression syndromes, including Paget-Schroetter syndrome, Nutcracker syndrome, May-Thurner syndrome and popliteal venous compression will be discussed. These syndromes are usually seen in young, otherwise healthy individuals, and can lead to significant overall morbidity. Aside from clinical findings and physical examination, diagnosis can be made with ultrasound, CT, or MR conventional venography. Symptoms and haemodynamic significance of the compression determine the ideal treatment method.

Endovascular stenting for treatment of Nutcracker syndrome: report of 61 cases with long-term followup

PURPOSE

We report the efficacy and safety of endovascular stenting for nutcracker syndrome at long-term followup.

MATERIALS AND METHODS

We retrospectively evaluated the endovascular stenting experience with 61 patients with a median age of 26 years. Symptoms were hematuria, proteinuria or flank pain. Median followup was 66 months.

RESULTS

Peak velocity in the aortomesenteric portion, and the anteroposterior diameter ratio of the renal hilum and the aortomesenteric portion of the left renal vein on Duplex ultrasound after stenting was significantly decreased compared to that on Duplex ultrasound before stenting (p<0.05). However, peak velocity in the hilar portion did not statistically differ (p>0.05). Symptoms resolved or improved in 15, 24 and 20 of the 61 patients within 1 week, and 1 and 6 months, respectively, after endovascular stenting. Symptoms remained unchanged in 2 patients and recurred in 1. A perioperative complication was noted in 1 patient, that is a stent that was mistakenly moved and poorly deployed in a left renal vein collateral required operative intervention. Postoperative complications included stent migration into the right atrium, stent protrusion into the inferior vena cava and stent migration into the hilar left renal vein in 1 case each.

CONCLUSIONS

Based on our long-term followup endovascular stenting is a safe, effective procedure in select adults. We recommend endovascular stenting as primary option for nutcracker syndrome.

The nutcracker syndrome

Left renal vein (LRV) compression, commonly referred to as the nutcracker syndrome or renal vein entrapment syndrome, is a rare and often overlooked condition. Anatomically, the LRV traverses the space between the superior mesenteric artery and the aorta in close proximity to the origin of the artery. In affected individuals, the LRV is subjected to compression between these two structures, resulting in renal venous hypertension. A review of published data on this condition reveals either case reports or small case series. The classic symptoms of nutcracker syndrome include left flank pain with gross or microscopic hematuria. Patients are often children or young adults, with a slight predisposition for women who may also present with pelvic congestion symptoms such as pelvic pain and dyspareunia. Most patients have disease symptoms for many years and nondiagnostic investigations before proper diagnosis can be made. Appropriate diagnostic work-up and treatment may help alleviate patient morbidity from this chronic condition. Although surgical repair has been the standard of care, more recently endovascular intervention has become the first line of therapy. This tabular review compiles published cases in the adult population during the period between 1980 and 2009.

Nutcracker phenomenon and nutcracker syndrome

Nutcracker phenomenon refers to compression of the left renal vein, most commonly between the aorta and the superior mesenteric artery, with impaired blood outflow often accompanied by distention of the distal portion of the vein. The nutcracker syndrome (NCS) is the clinical equivalent of nutcracker phenomenon characterized by a complex of symptoms with substantial variations. Depending on specific manifestations, NCS may be encountered by different medical specialists. Although it may be associated with substantial morbidity, the diagnosis of NCS is often difficult and is commonly delayed. Diagnostic and treatment criteria are not well established, and the natural history of NCS is not well understood. We performed an initial review of the literature through MEDLINE, searching from 1950 to date and using the keywords nutcracker syndrome, nutcracker phenomenon, and renal vein entrapment. We performed additional reviews based on the literature citations of the identified articles. We attempted to elucidate clinical relevance of these conditions and their prominent features and to summarize professional experience.

Management of renal nutcracker syndrome by retroperitoneal laparoscopic nephrectomy with ex vivo autograft repair and autotransplantation: a case report and review of the literature

Introduction

Nutcracker syndrome (NCS) is caused by a compression of the left renal vein between the aorta and the superior mesenteric artery (SMA). It results in left renal venous hypertension, and the subsequent development of venous varicosities of the renal pelvis, ureter, and gonadal vein.

Case presentation

A 21-year-old Chinese woman was admitted with a seven-month history of unilateral severe hematuria. On admission, she was identified as having nutcracker syndrome. The patient was treated with retroperitoneal laparoscopic donor nephrectomy and renal autotransplantation. The patient underwent retroperitoneal laparoscopic donor nephrectomy using a retroperitoneal three-port technique with ex vitro autograft repair and subsequent renal autotransplantation into the iliac fossa. In order to shorten the hot ischemia time and improve the patient's cosmetic outcome, a minor oblique incision in the left, lower quadrant was prepared in advance of the laparoscopic donor nephrectomy for use as a site for the autograft to be procured through the retroperitoneal space and as a transplant site for the autograft. Two days after the operation, the patient's symptoms subsided. Serum creatinine before and after the operation were 53 mmol/L and 55 mmol/L, respectively. The patient had normal renal function during a follow-up three months after the operation.

Conclusion

The treatment of nutcracker syndrome by retroperitoneal laparoscopic nephrectomy with ex vitro repair and autotransplantation is a simpler and less invasive procedure than open surgery. Moreover, a minor incision on the left hypogastrium can shorten the autograft's hot ischemic time and improve patients' cosmetic outcomes, especially in young women.

[Nutcracker syndrome managed by simple surveillance]

Nutcracker syndrome is caused by compression of the left renal vein between the aorta and the superior mesenteric artery where it passes in the fork formed at the bifurcation of these arteries. The phenomenon results in left renal venous hypertension. The syndrome is manifested by left flank and abdominal pain, with or without unilateral haematuria. The nutcracker syndrome has been treated in various ways. We report one case of the syndrome and discuss the place of surveillance in its management.

Laparoscopic splenorenal venous bypass for nutcracker syndrome

Nutcracker syndrome is a rare entity caused by extrinsic compression on the left renal vein as it crosses between the superior mesenteric artery and the aorta. It can clinically present with flank pain and hematuria. Accepted treatments include open vascular bypass procedures or endoluminal stenting. We present the first description, to our knowledge, of a laparoscopic splenic vein-left renal vein bypass to relieve the outflow obstruction. The patient, a 29-year-old woman with debilitating left flank pain, presented with nutcracker syndrome. Left renal vein outflow was obstructed at the level of the intersection between the aorta and the superior mesenteric artery. The option of laparoscopic splenic to left renal vein bypass was discussed and performed. A five-port transperitoneal approach was used. Meticulous vascular control was achieved with numerous laparoscopic vascular bulldog clamps. With completely intracorporeal suturing techniques, the splenic vein was anastomosed to the superior aspect of the anterior left renal vein. Total warm ischemia time was 37 minutes. The anastomosis was watertight immediately upon unclamping. Interestingly, upon unclamping, the luminal diameter of the splenic vein appeared to increase to twice its native diameter. The proximal left renal vein appeared less distended, indicating preferential venous outflow through the newly created venous bypass. Blood loss was minimal, no intraoperative or postoperative complications occurred, and the patient's symptoms improved. This report continues to augment the indications for laparoscopic surgery in even complex, urologic vascular situations.

Entrapment syndromes

Entrapment syndromes represent a pathological process that vascular specialists encounter infrequently. However symptomatic patients are often young with impaired quality of life and successful treatment can produce great benefit, making knowledge of these conditions essential. The purpose of this review was to bring together the entrapment syndromes to understand and gain consensus on the aetiology, pathogenesis, diagnosis and modern management of these rare and interesting vascular disorders. This includes entrapment syndromes of the popliteal artery, superior mesenteric artery, coeliac artery, renal vein and iliac vein.

Current trends in the diagnosis and management of renal nutcracker syndrome: a review

Nutcracker syndrome is caused by compression of the left renal vein between the aorta and the superior mesenteric artery where it passes in the fork formed at the bifurcation of these arteries. The phenomenon results in left renal venous hypertension. The syndrome is manifested by left flank and abdominal pain, with or without unilateral haematuria. Other common presentation is as "pelvic congestion syndrome" characterized by symptoms of dysmenorrhea, dyspareunia, post-coital ache, lower abdominal pain, dysuria, pelvic, vulvar, gluteal or thigh varices and emotional disturbances. Likewise compression of the left renal vein can cause left renal-to-gonadal vein reflux resulting in lower limb varices and varicoceles in males. Its diagnosis is based on history and physical examination, basic lab tests to exclude other causes of haematuria, cystoscopy and ureteroscopy to confirm unilateral haematuria and exclude other causes of this sinister symptom. Sequence of imaging has more or less been rationalised to USS with Doppler studies, CT or MR angiography and finally phlebography with renal vein and IVC manometery to confirm the diagnosis.

Mesoaortic compression of the left renal vein (nutcracker syndrome): case reports and review of the literature

Compression of the left renal vein between the aorta and the superior mesenteric artery has been termed the nutcracker syndrome. Obstruction of left renal vein outflow results in venous hypertension with the formation of intra- and extrarenal collaterals and/or the development of gonadal vein reflux. To date, a variety of clinical symptoms due to mesoaortic compression of the left renal vein (nutcracker syndrome) have been described. It is not known what pathophysiological variables play a role in the different clinical manifestations of nutcracker syndrome. We report two patients representing the two different forms of the condition. In the first, hematuria and left flank pain resolved in a young man after successful renocaval reimplantation. In the second, symptoms of pelvic congestion due to pelvic varices improved in a middle-aged woman after successful embolization of the gonadal vein and pelvic collaterals. This report reviews the pathophysiology, presentation, diagnosis including radiographic findings, management options, as well as the current literature on nutcracker syndrome.

Endovascular stenting in the treatment of pelvic vein congestion caused by nutcracker syndrome: Lessons learned from the first five cases

BACKGROUND

Compression of the left renal vein between the aorta and the superior mesenteric artery is a rare but possibly underestimated condition. Surgical correction (42 cases reported in the literature) can be performed by means of a variety of different techniques. Although endovascular stenting is well accepted for iliocaval occlusive disease, it has been poorly evaluated in this indication. We describe five patients who were treated for nutcracker syndrome by using stenting and analyze the nine cases previously reported.

METHODS

From November 2002 to September 2004, five women (mean age, 34.7 years) were admitted for endovascular treatment of a nutcracker syndrome. They all had incapacitating pelvic congestion syndrome, including two with a history of left ovarian vein embolization; moreover, two had left lumbar pain, and three had hematuria. The mean preoperative venous disability score was 2.4. The patients underwent a gynecologic examination and laparoscopy to eliminate other causes of pelvic pain. The laparoscopy revealed large pelvic varicose veins and no signs of endometriosis. Duplex scan, computed tomographic scan, and iliocavography revealed left renal vein compression, with proximal distention and collateral pathways, with dilatation and permanent reflux in the left ovarian vein in the three patients who had not had prior embolization. The mean renocaval pullback gradient was 4.3 mm Hg. A percutaneous endovascular procedure, during in which a self-expanding metallic stent was implanted, was performed under general anaesthesia.

RESULTS

Technical success was achieved in all cases. One case of stent migration occurred: the stent was pulled down in the inferior vena cava, with uneventful follow-up (mean, 14.3 months). One month later, patients were all improved and stents were patent at the duplex scan examination, without restenosis. The mean venous disability score was 1. No further left ovarian vein reflux was evident at duplex scan in patients who did not have prior embolization. Pelvic pain recurred in one patient who had initially improved, and endometriosis was diagnosed 15 months after the procedure. Two other patients, who received 40-mm-long stents, had a secondary recurrence of the symptoms caused by stent dislodgement. The two other patients were asymptomatic.

CONCLUSIONS

This study shows that stenting is feasible, but some guidelines should be followed, mainly the use of long stents protruding into the inferior vena cava. Stenting can eliminate the symptoms of the condition, and the technique is only very slightly invasive. Further experience and follow-up are needed before accepting such a procedure for treatment of the nutcracker syndrome.